The system consists of eight planets, several dwarf planets (including Pluto , the site of the main outpost for the ISDF's outer-system operations) and two large belts of asteroids. The first, situated between Mars and Jupiter, is the former site of the Cthonian planet Icarus; the current belt represents what remains of the system after its destruction. The Kuiper belt, which is much larger and situated beyond the orbit of Neptune, contains several dwarf worlds - including both Pluto and the Dark Planet.
There are several interstellar portals situated within the system, each leading to a different alien system. The Stargate on Venus connects to Alpha 007, the Pegasus Device connects Ganymede and Elysium, and an artificial wormhole leads from the Dark Planet to the Core System.
- Mercury, a small rocky planet orbiting close to the sun
- Venus, a hot and caustic planet with an incredibly thick atmosphere
- Earth, a temperate planet home to various forms of life
- Luna, a barren rocky moon
- Mars, a dusty red planet previously occupied by the Olympian Council
- Icarus , former homeworld of the Cthonians and now little more than a collection of asteroidal debris
- Jupiter, a massive gas giant
- Saturn, a smaller, ringed gas giant
- Titan, a moon rich in both hydrocarbons and water ice
- Uranus, the system's first ice giant
- Neptune, the second and slightly smaller ice giant
- Pluto, an ice dwarf near the edge of the system
- The Dark Planet, a biometalloid of uncertain origin